Tampering with packaging containers and particularly food containers has led to the development and increasingly frequent use of tamper resistant lids for such containers. It is now imperative that all food containers have some type of tamper protection.
There are various types of tamper resistant protection. Some are in the form of seals over lids and caps while other types of protection is in the form of tear off seals beneath lids. These devices are intended to provide evidence of tampering to the user. Any damage to the protective seals is a warning not to consume the product inside the container.
For cups, tubs or bowl like containers for foodstuffs various tamper evident protection devices are used. One popular method is to add a shrink band plastic seal around the periphery of a lid. This type of seal makes it difficult to get the lid off beneath the seal with some evidence of damage to the shrink band of plastic. This seal is a band of plastic film that shrinks when heated. Any tearing, stretching or damage to the plastic seal will provide evidence of tampering and provide a warning by being evident to the user.
Another popular and widely used method of providing a protective seal is with some form of tear off band around the periphery of a lid. To gain access to the contents of the container requires tearing the band off the lid or container. The tear band essentially prevents removal of the lid without stripping away the band. Any attempt to remove the lid to gain access to the contents without removing the tear band will usually result in visible damage to the tear band. This damage protects the user by providing evidence of tampering.
These tamper evident protection devices are under constant development and improvement. One such improved protection device is disclosed and described in U.S. Pat. No. 5,115,934 of James A. Nelson the same inventor as the system disclosed herein. The device of this patent is a substantial improvement of tamper evident tear bands. Most tear bands provide protection but can be defeated. The device of this patent provides a tear strip melt band that has deformable links and a locking system that is extremely difficult to defeat after it is installed.
The lid is mounted on a container and the locking tear strip folded down around a flange on the periphery of a container. This causes deformable links joining tabs around the tear band to bulge. Heating the tear band causes the links to melt and deform into the space between the tabs securely locking the lid on the container. The deformable links so securely lock the lid on the container that it is nearly impossible to remove the lid without breaking one or more of the links providing clear evidence of tampering.
All these devices, of course, slow up production of food packaging. The lids with the tamper evident seals, be it plastic film shrink bands or tear bands must be carefully installed to provide the required protection but also to prevent damage to the seal which might mistakenly appear to be evidence of tampering. In some cases, the lid or shrink band plastic is manually installed which is a disadvantage.
Another disadvantage of the shrink band seals is the heat applied to shrink the plastic shrink band seal tightly around the periphery of the lid. Shrink band seals are pre-formed and manually placed on the container after the container is filled and the lid put on. The filled container with the shrink band seal is then passed through an oven on a conveyor belt to heat and shrink the plastic seal on the container. A disadvantage of this method is that as a result the entire container and its contents are heated. In many cases the heat can have a detrimental effect on the contents such as decreasing shelf life or at the very least change the flavor or character of the contents.
Therefore it is one object of the present invention to completely automate lid dispensing, mounting and sealing.
Yet another object of the invention is to provide a lid dispensing, mounting and sealing apparatus that avoids heating the contents of the containers.
Still another object of the present invention is to fully automate the lid installation and sealing after containers are filled.
Another object of the invention is to provide a unique automated lid dispensing apparatus.
Yet another object of the invention is to provide a lid dispensing, mounting and sealing apparatus that is adjustable to accommodate different size containers.
Still another object of the present invention is to provide a lid sealing apparatus for tamper resistant containers that use either tear bands or shrink band seals.